US476380A - Beam compasses - Google Patents

Description

(No Model.)

H. HASLAM. BEAM GOMPASSES.

No. 476,880. Patentd June 7, 1892.

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I'IENR Y HASLAM, OF NEN BRITAIN, CONNECTICUT, ASSIGNOR TO JUSTUS A. TRAUT, OF SAME PLACE.

BEAM COMPASSES.

SPECIFICATION forming part of Letters Patent No. 476,380, dated June '7, 1892,

Application filed December 15, 1891. Serial No. 415,102- (No model.) I

To all whom it may concern:

Be it known that 1, HENRY HASLAM,a citi- Zen of the United States, residing at New Britain, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Beam-Compasses, of which the following is a specification.

This invention relates to beam-compasses or trammels, the object being to furnish a trammel having two compass-points and having pencil-carrying means adapted, also, for effecting the fine adjustment of the pencil.

In the drawings accompanying and forming a part of this specification, Figure 1 is a side elevation of a beam-compasses or trammel embodying my present invention. Fig. 2 is aplan view of the same. Fig. 3 is a view similar to a portion of Fig. 2 for illustrating the method of adjusting the pencil. Fig. 4 is an enlarged sectional view in line a a, Fig. 1, showing the pencil-holder in plan view. Fig. 5 is a side elevation of the parts shown in Fig. 4.

Similar characters designate like parts in all the figures.

The beam-compasses shown in the drawings is provided with the usual beam or trammelbar 2, on which the two heads 4 and 6 are fitted to slide in the ordinary manner, said heads being usually furnished with the shoes 3 and 5 for clamping the heads to the bar or beam 2. Said heads at and 6 are furnished with the usual compass-points 8 and 10, respectively, which points are fixed in the lower ends or sockets of the heads after the usual manner.

The pencil-holder consists of a clamp fitted at one end to grasp the point 8 of the compass and fitted at the opposite end to similarly grasp the pencil 7. In practice I make said point 8 of the diameter of the pencils more generally used, so that the clamp will be reversible, thus enabling the carpenter or other workman to apply either end of the clamp to the point 8 and then place the pencil in the opposite end of said clamp. This feature of reversibility of the clamp facilitates the use of the device by saving time and requiring the least attention on the part of the user and the least cost of manufacture.

The clamp consists of the two sides or clampplates 1-1 and 16, constructed with parallel grooves forming bearings for receiving the trammel-point and the pencil, respectively, as will be more fully understood from a comparison of the figures of drawings and especially of Figs. 4 and 5. Said clamp-plates are held together and are clamped and unclamped by means of a thumb-screw 15, which is shown passing through the clamp-plate 14: and engaging by its thread the opposite clamp-plate 10. Vhen the clamp is in place on the compass-point, as shown in Figs. 1 and 2, the pencil should of course projecta little below said point, as shown in Fig. 2, so that the point will clear the surface being marked by the pencil.

For adjusting the radius of the compasses when the heads have been set on the beam to approximately the required distance, the user slightly loosens the thn nib-screw 15 and swings the clamp-plates on the compass-point 8 to carry the pencil either outward or inward, as the case may require.

In Fig. 2 the pencil is shown set for drawing the line as, the opposite compass-point 10 being the center of the circle. In Fig. 3, with the same center and the same setting of the heads on the beam, the pencil-carrying device is shown swung back to bring the pencil-point to the line y. By this means, it will be seen, a considerable adjustment of the radius of the compasses maybe readily and quickly effected without any adjustment of either head on the beam.

For retaining the pencil-carrier on the compass-point 8 when the pencil is removed from said carrier, I provide in some cases a collar or shoulder 20, Fig. 1, immediately belowthe carrier to serve as a stop therefor. In some cases, however, said collar is omitted, as in Fig. 5, so that the carrier may be removed by sliding it off from the point of the compasses without removing the pencil therefrom, the hearings in the pencil-carrying clamp being formed parallel with each other, the working position of the pencil-point is not changed 5 when this is swung from one position to another, as shown, for instance, in Figs. 1 and 3. Having thus described my invention, I claim The improved beam-compasses herein described, consisting in the combination, with same in position longitudinally of the train the beam and apair of heads adjustable theremel point, substantially as shown and deon and each provided with a compass-point, scribed.

of the ad justable pencil-carrying clamp hav- HENRY HASLAM. 5 ing parallel bearings for receiving the tram- Witnesses:

mel-point and pencil, respectively, and means ARTHUR GRUMBT,

for closing said clamp and for holding the J. A. TRATTT.

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